Pulse Air BOOOO BOOOO

[bubby-joe]

I've ordered the plugs and gaskets to get rid of the pulse air plumbing and now have a real problem, the threads came out with adapter in the heads there is no thread left for the plugs to catch.  Might a helicoil fix this or am I looking at a total rebuild to replace both heads for new ones.  Another option might be a 3/8ths tapered thread pipe plug to fill the hole.  The problem started with the previous owner cross threading the adapter and no never seize PUTZE..  some people should never pick up a tool he's one of them.  I'm hoping not to loose the whole season to this.   REDNECK fixes allowed.

Thread for the plugs part#07119919143 is 18mmX1.50pitch according to the real OEM parts list but an 18mmX1.50 sparkplug is a little bigger yes I have 4 of them from a 5 hp ELTO 4cyl outboard motor. NO IT NEEDS A CARB

[Bob_Roller]

Installing a threaded insert, or rethreading the hole for a larger plug will work .

Not really going to be seen by anyone but you .

[montmil]

Well, B'Joe, you have only a few options; outside of scoring some used heads...

The helicoil would probably work. You may not need to first drill as the aluminum head could be tapped fairly easily. Grease the tap to catch most of the chips and either vacuum out the swarf or blast it out the exhaust port at startup.

Wonder how much that tap costs? Gotta be cheaper than a replacement head.

A pipe thread plug would also work but I might wonder if the end of the plug may extend into the exhaust tract and generate a hot spot during ops. Unsure if that might cause a problem.

It's a fixable problem. BTW, other forum and site notes regarding the air plumbing removal instruct the owner to not use anti-sieze on the threaded plugs. Never heard a reason why not to but I didn't use any when I modded both my R65s.

Good luck. Let us know how it turns out.

[tvrla]

Those plugs fall out sometimes (actually blow out and get lost) so it's not a good idea to anti seize them. If it could be done without warping the head, I'd weld it up. Otherwise, install an insert or tap it for the next size up.

[raymr]

Where do I find out some more about this plumbing removal? Mine runs fine but I have nothing to compare to, so I don't know what I'm missing.

[bubby-joe]

To dirty to get a good weld over 30 years of carbon and dirt and oil, the hole has a bottom in it with the engine running exaust and downward angle will prevent chips from entering the engine dry wilth very small chip breaks should keep it very clean running after will remove the chips but no Beemer should sound like that.

I googled R-65 pulse air removal there is really good pictures in that.

URL (http://www.webbikeworld.com/Motorcycle-technical-articles/pulse-air/)

part numbers included in article.

My problem now comes to where to find 3/8 NPT starting taps the plugs are easy check my old marine junk used to be fairly common on inboard marine engines.  REDNECK KNOWLEGE CHANNEL

I believe my tread removal may also have been due to disimilar metals and electrolosis combined with hot and cold running cycles.......

[nhmaf]

I believe that the same type of galling process that can so frequently cause the heartbreak of stripped exhaust nut threads on these engines can also cause-or at least contribute- to stripping the threads on these pulse air intakes at the head.   I either avoid messing with the attachment point at the head entirely, or if I must take them off, I do use anti-seize in hope that will prevent permanent bonding and subsequent thread damage upon future removal attempts.   IT is probably a bit of a coin-toss - slightly increase the risk of the parts coming out from vibration versus galling the threads if you do have to remove it later on.   Choose your poison!!

[Rob Valdez 79 R65]

Drill & tap it to the next size larger - NBD.

Use anti-seize intended for high temperature.  You will never be removing them.

[bubby-joe]

OK all fixed, went with 3/8 NPT plugs teflon tape on tapered thread just snug then when warmed up tighten 1/4 turn no more or it could crack the heads.

Problems solved with the pulse-air removal

1 Deceleration lean pop GONE
2 Carbs now setup easier 10 miles to warmup then adjust the carbs the BINGS get a 1 year trial lease on life then maybe the mikuni replacements.
3 Now Idles below 1100-1200RPM no more surging and stalling at idle now down to 850RPM and smooth.
4 Better off the line performance all round a better driver no more stumble or flat spot off the line

Thanks everyone for joining in.

It went from an OH CRAP DAY to ALLLLLLL RIGHTTTTT in less than 1/2 hour even going for parts and borrowing the proper tap

[Bob_Roller]

Good to hear that things worked out for you .

At least we now know there is another option available for repairing these threads when they get stripped out .

Time for an adult beverage, or two !!!

[montmil]

850 rpm idle on your R65 is probably the lower limit you'll want at idle. At those revs, very little oil is being "squirted" onto the timing chain and sprockets. It's a crude system -and it is a copper pipe that squirts oil into the timing case cavity- that depends on engine revs for lubrication. I keep my R65s closer to 900-1000 idle speed... especially since I replaced the chain on the '81.

[bubby-joe]

Good to know thanks I redid to 950RPM what a difference I didn't realize I had 3 years of bad running at 40MPG might do a little better because I won't be reving the engine to keep it running at a light or stop sign any more.